1. Field of the Invention
This invention relates to remote control wiring systems in which high voltage load circuits are controlled by relays which are disposed in a low voltage subsystem and are controlled by switches in the subsystem.
2. Description of the Prior Art
Remote control wiring systems are designed to provide substantial flexibility; for example, a plurality of separate load circuits may be simultaneously controlled from a single switch. Alternatively, the system may provide for the control of a single load circuit from a plurality of locations. The switches in each case are normally connected to energize relays in a low voltage subsystem which permits the employing of relatively small gauge wire. Because of the distance between the relays and the switches this small gauge wire may be of substantial length.
A conventional relay employed in such a system normally draws approximately 0.5 ampere. The remote control switches employed for controlling the relays are normally rated at three amperes. Therefore, such a switch can normally control some six relays connected in parallel. One problem that arises in connection with such systems in that the transmission of even three amperes over the length and gauge of wire employed in such remote control wiring systems can cause a substantial voltage drop. This drop may be of such magnitude that the relays controlled the switch may not operate properly. Thus, in installing such a system it is necessary to use care as to the length and gauge of wire employed and under some circumstances it may be necessary to limit the versatility of the installation in order to limit the length of wire or alternatively to employ somewhat heavier gauge wire with resultant increase in cost.
In some cases in order to utilize the full advantages of a remote control wiring system, it may be desirable to control, for example, all of the lights and other appliances on the entire floor of a building from a single switch located near the entrance. In such case, the number of relays to be actuated from the single switch may exceed the six referred to above and may even include all 24 relays which fit into a normal relay box or panel. Such a use raises two problems. If the switch is used to control 24 relays, for example, it can be appreciated that the switch would have to handle a total of 12 amperes which would exceed the current capacity of switches normally employed in such installations. Secondly, even if a switch of adequate size to handle this current were employed, the voltage drop caused by a current of this magnitude would be of such magnitude that the relays would not operate properly or the length of wire which could be employed would have to be severely limited or the gauge of the wire would have to be increased, thereby reducing the versatility and economy of such remote control wiring systems.
By the present invention, these limitations of prior art remote control wiring systems are avoided and a control arrangement is provided which permits the utilization and simultaneous opening or simultaneous closing of a substantial number of load circuits without exceeding the capacity of the switches and without introducing an undesirably high voltage drop despite the use of a substantial length of control wire of relatively small gauge.
Accordingly, it is an object of this invention to provide a remote control wiring system which provides for the effective control from a single switch of a greater number of load circuits than has heretofore been possible.
It is another object of this invention to provide a remote control wiring system which permits the use of small gauge wire despite the substantial length required and which permits the control of the relays without any risk of a voltage drop in the wiring system of magnitude sufficient to interfere with the proper operation of the relays.